Projects When to apply body filler?

that would work.

 

Anyone mention...not reading all the replies...making sure the panel is sealed? I'e...tack weld in a patch.. Got daylight? Probabably not a good time for filler

 

Just a little note:

Today's primer, filler, and paint are not yesterday's primer, filler, and paint.

Those days have passed.

 

If you use a quality filler it doesn’t shrink. Only the cheap off brand fillers shrink.

 

Some of us march to the beat of a different drum. I will seal the metalwork with the the aluminum pigmented non-leafing moisture cured primer. I usually use Rage body filler then I'll put a coat of my primer over it. This nonporous primer seals off oxygen, moisture, and solvent penetration. I've had no problem with shrinkage using this technique. I'll use a surfacing primer over it

 

I don't recall who said it a few post back, but i grind out body filler on a regular basis that has no rust behind it. I took autobody in high school, been 36 years now, and other than that shit they sell at Walmart, i didn't realize there was so much thought process put into body filler application! Grind the area for adhesion, mix it, apply it, block it, primer it. If ya gotta overthink body filler, I'm probably way too stupid to be in this group lmao! Sorry, back to actually applying and sanding body filler

 

And it one thing that’s has improved

 

Hey,,,, ?!? when did body filler get so smart?

Around these parts (salted winters) all we ever see is failed body filler. I’m certain there’s plenty that don’t but we don’t see them because no reason to look or grind it out right?

 

Unfortunately this is way too common an attitude with technicians and the reason I am in body shops far too frequently dealing with "filler problems."

To the OP here is a thread I did on Body Filler basics: https://www.jalopyjournal.com/forum/threads/body-filler-basics.1180243/

And you should never use solvents to wipe down body filler.

 

I would love to know what the hell this guy did here. This car has get this all over the place and the paint looks fairly fresh.

 

I know exactly what he did. He didn't get all the rust removed, he filled holes with bondo, and he didn't seal the backside. A sure case of the "fix" lasting a couple years at best. I see it all the time, even here in the HAMB. Guys just grinding the top flakes off the rust and leaving the rust down in the pits. Some say they put "rust convertor" on it so it won't come back. Bull.

 

Used car lot fix mentality.
longevity is not the goal.

The lot wants to pay as little as possible to get the car looking as good as possible.
Anyone who’s done this more than once knows all the work is in the preparation. The success lives and dies in the preparation. Want it cheaper and faster ??? Slash the prep, it lasts long enough for the payment to clear and that’s the goal.

 

So 3M is off-brand?

It shrinks. So do all of the Evercoat product I have used.

Neither shrinks a lot, but enough that they would be noticable under gloss black, if not allowed to fully shrink, before sanding.

 

That’s why I’ve been letting the filler and primer cure on my 40 tudor project. Is 30 years enough?

 

Worked in the same collision shop for close to 14 years. So I got to see the same car several times. Never remember any filler shrinkage. But we were not a production shop either. Seen clears die back and an occasional sand scratch. We finished off filler with at least 180. Primer generally had a day or two before painted.
A friend of mine does resto work. He mixes everything on a scale. Even filler. Same color every time. Filler and primers are given time to gas out. He will “open up” primer (first round of blocking) and give it time before final sanding.
His stuff looks great.

 

Maybe give it 5-10 more.

 

Attitude? No attitude from me. I'm like Fargo said in a brake thread, his shit stops, my body work lasts. But I guess I'm just lucky because I'm not a scientist or 70 years old i don't know what I'm doing. I'll get this figured out sooner or later lmao. But until then I've got cars to build and filler to sling. You all hash it out

 

Different take on the same question:
Has anyone seen a filler manufacturers instructions for use that state 'use over' anything?
I haven't and just spent a few minutes looking at Evercoat and 3M and saw nothing.
I've done both direct and over epoxy over the years with no failures.
But, (knew that was coming didn't ya?), on one bodywork web site that I've been on for years there have been a couple of tests done. Bare metal test coupons prepared with epoxy and just sanded to 80 grit. After a full cure, the coupons were bent in a vise. The filler over epoxy seperated, but after a pretty severe bend.
The only manufacturers that I've personally seen written recommendations for filler over epoxy have been the makes of epoxy.
That stuff is great for projects that take a while to complete, like all of mine. Use it on everyone, but grind off the areas that need a lot of filler work. Small spots, just hit the epoxy with some 80 and fill on top.

 

Sooooo
The filler needs that homogeneous molecular seal of epoxy broken open,,,

The good thing is that the epoxy doesn’t need to come all the ways off. The filler can go over the epoxy Much like icing and primer can go over scuffed up clear that’s well adhered.

You’re going to eventually find out if the epoxy was well adhered to the base metal much like you find out if the clear was well adhered.

 

From their website. There is also a TDS for every product on the site that lists what substrate each product can be applied over.

 

If your filler is regularly shrinking your are undercatalizing it.

 

Remove filler sanding dust with clean/dry compressed air or a vacuum cleaner followed with a tack cloth. Inspect for pin holes in the filler and fill before priming.
Solvent use on bare filler will penetrate causing uncertainty as too when, if at all, the solvent has evaporated.
Many solvents leave residue which would not be good.

 

DP40 AND DP90 were the same product only different colors. New stuff is DP90LF black, DP40LF green gray, white and grey also available.

 

http://www.evercoat.com/images/ePIM/original/TDS_100125_RAGE-ULTRA-7.2017.pdf

https://www.myrv14.com/buildlog/20160510/p-196_dplf_epoxy_primer-9-13.pdf

 

https://ppgrefinish-na.uberflip.com/i/982460-custom-restoration-guide-2018/45?
Filler over epoxy details

Ppg DF fillers as listed in their tech sheets as ok to use over their epoxy.
https://images.oreillyauto.com/parts/img/documents/ppg/p-101+df+body+fillers+6+15.pdf

 

Remo says why take a chance?

 

http://www.evercoat.com/faq/us/

 

you keep showing us instructions, you'll take all the fun out of it!

Bottom line, there are several ways to do it, that work fine...and still, keeping your car inside most of the time is the best way to make the paint last a long long time.

 

Cars rust less when they stay in motion.

 

Mostly...but it depends where you drive them, and when